Allogeneic strains of normal mice sharing the major histocompatibility complex (H-2k) with AKR exhibit little, if any, reactivity against AKR leukemia cells in vivo. In the planned experiments, cells from several H-2k strains of mice will be sensitized in vivo or in vitro and tested for reactivity against AKR normal and leukemic cells. Immunogens to be used for sensitization include irradiated AKR leukemia cells, solubilized cell surface antigens from AKR leukemia cells, and leukemia cells from other animal species whose leukemia has characteristics which are similar to AKR leukemia. Sensitized cells from H-2k compatible strains of mice that have acquired reactivity against AKR leukemia cells, without a marked increase in reactivity against normal AKR tissues, will be used for adoptive immunotherapy of leukemic AKR mice. BIBLIOGRAPHIC REFERENCES: Bortin, M.M., Truitt, R.L. and Rimm, A.A.: Nonspecific Adoptive Immunotherapy of T Cell Acute Lymphoblastic Leukemia in AKR Mice: A Model for the Treatment of T Cell Leukemia in Man. In: The Handbook of Cancer Immunology, (H. Waters, ed.), Garland Publishing, New York, in press, 1978. Bortin, M.M. and Truitt, R.L.: AKR T Cell Acute Lymphoblastic Leukemia: A Model for Human T Cell Leukemia. Biomedicine, 1977, in press.